Improving the fastness of dyed organic derivative of cellulose textiles by impregnation with cyanamide



Patented Apr. 27, 1948' IMPROVING THE FAsTNEss F DYED ORGANIC DERIVATIVE or CELLU- LOSE TEXTILES BY IMPREGNATION WITH CYANAMIDE Henry Dreyfus, London, England; Claude Bonard, administrator of said Henry Dreyfus, deceased, assignor to Celanese Corporation oi America, a

corporation of Delaware No Drawing. Application August 15, 1944, Serial No. 549,625. In Great Britain August 26, 1943 Claims.

This invention relates to the incorporation of difiicultly soluble nitrogenous compounds in textile materials for various purposes, for example, to improve fastness of dyes, to impart aiiinity for acid dyes, to modify lustre, or to fix dyes, pigments, sizes and the like upon the material.

It is very convenient to be able toefiect application of such nitrogenous compounds, or components from which the compounds can be prepared on the material, by a simple padding or other mechanical impregnation operation using an appropriate aqueous solution. However, many nitrogenous compounds useful for these purposes, or components from which they can be produced, are of such low solubility in water that it is diihcult to apply the requisite proportion of substance in this way. Thus in the case of melamine, a substance useful for improving the resistance of colourations on cellulose acetate materials to combustion products of. coal gas, the solubility in water at ordinary temperature is less than 0.5% and at 50 C. is only about 1%. Again, the solubility of di-cyandiamide in water at ordinary temperature is only of the order of 2%. In padding a textile material with a liquid it is not practicable to arrange to leave in the material much more than about its own weight of liquid. In the case of melamine, therefore, it is only practicable to incorporate in this way about 0.5% on the weight of the material by padding at ordinary temperatures.

It has been found that cyanamide can usefully be employed for'preparing textile materials carrying such nitrogenous compounds difilcuitly soluble in water. Cyanamide is very soluble in water, even at ordinary temperatures, and by heat treatment, even at temperatures below 100 C., or reaction with an aldehyde, or both, can be converted into difiicultly soluble nitrogenous compounds (including water-insoluble products).

Conveniently the cyanamide is applied to the textile material in the form 01 an aqueous solution, which may contain an acid, and the material then dried and heated to a temperature which will convert the cyanamide into a nitrogenous compound of but little solubility in water. For example the material may be heated at 90 to 150C. As the cyanamide is very soluble in water it is easy to apply a substantial proportion, e. g. 5% or more, by a single impregnation with an aqueous solution and so to incorporate in the material a proportionately large amount 01 the soluble nitrogenous compound. The acid can be acetic or other organic acid.

An aqueous solution 01 cyanamide is conveniently prepared by extracting commercial calcium cyanamide with water at a fairly low temperature, say 40 C. or lower, filterin passing carbon dioxide through the filtrate until the calcium is substantially precipitated as carbonate, again ether and in fabric, yarn, loose staple fibre, or

other form.

The treatment may be applied for example to a cellulose ester or ether textile which has been coloured with a dye, e. g. a violet or blue aminoanthraquinone dye, which is insufliciently resistant to the action of combustion products of coal gas, so as to improve its resistance to this agency. Examples of such dyes are 1:4-diamino-anthraquinone and its N-alkyl and N-aryl derivatives, e. g. 1:4-di(methylamino)-anthraquinone, lmeth'ylamino-4-(beta-hydroxy-ethylamino) anthraquinone, 1-amino-4-methylamino-anthraquinone and 1-amino-4-phenylamino-anthraquinone.

The invention is illustrated by the following example;

Example Acellulose acetate fabric. dyed to a medium blue shade with 1-methylamino-4-beta-hydroxyethylaminoanthraquinone, is padded with a 6% aqueous solution of cyanamide containing 50 cc. of glacial acetic acid per litre, the padding being conducted so that the fabric retains about its own weight of the solution. The fabric is then dried and baked for 20 minutes at C. As compared with the untreated dyeing the treated dyeing possesses a considerably increased resistance to the combustion products of coal gas.

, Having described my invention, what I desire to secure by Letters Patent is:

1. Process for improving the color fastness of dyed textile material which comprises impregnating a dyed textile material having a basis of an organic derivative of cellulose with an aqueous solution of cyanamide and then drying and heating the impregnated material until a dimcultly soluble nitrogenous compound is formed.

2. Process for improving the color iastness of material and then heating at a temperature 01 110-150" 0., until a difflcultly soluble nitrogenous compound is formed.

3. Process for improving the color fastness oi' dyed textile material which comprises impregauaeao cellulose acetate textile material colored with an amino-anthraquinone dyestufl, drying the material and heating it at a temperature of 110-150 (7., until a diincultly soluble nitrogenous com- HENRY DREYFUS.

REFERENCES CITED The following references are ofrecord in the 5 pound is formed.

nating a dyed textile material having a basis m 316 is patent:

of cellulose acetate with an aqueous solution of cyanamlde and then drying and heating the impregnated material until a difllcultly soluble nitrogenous compound is formed.

4. Process for improving the color fastness of dyed textile material which comprises impregnating a dyed textile material having a basis of cellulose acetate with an aqueous solution of cyanamide, drying the impregnated material and then heating at a temperature of 110-150 C., until a difficultly soluble nitrogenous compound is formed.

5. Process for improving the color fastness of dyed textile material which comprises impregnatingwith an aqueous solution of cyanamide, a 25 UNITED STATES PATENTS Number Name Date 1,985,248 Ellis Dec. 25, 1934 2,123,152 Rivat July 5, 1938 2,176,508 McNally Oct. 17, 1939 2,234,889 Boulton Mar. 11, 1941 2,234,905 Tallis Mar. 11, 1941 2,247,353 Auer July 1, 1941 20 2,318,464 Cameron May 4, 1943 2,331,670 Ericka Oct. 12. 1943 FOREIGN PATENTS Number Country Date 537,964 Great Britain July 15, 1941 

